In the past, it has been known to use a truck to haul different types of trailers having loads on the trailers. In this way, trucks can be engaged and disengaged to different types of trailers, thereby increasing the versatility of the trucks and permitting them to haul different types and combinations of trailers.
However, several types of loads cannot be easily maintained on trailers having a flat surface. For example, loads having a curved configuration, such as coils of metal, tanks or pipes, cannot be easily transported on a trailer having a flat surface.
In addition, government highway regulations require trailers to have a certain number of axles for types or weights of loads. For example, it is common that the total weight is a function of the number of axles, the inter-axle distances and whether or not the axles are in clusters or separated. Also, highway regulations generally require the axles to be at specific longitudinal positions along the longitudinal axis of the trailer frame depending on the type of train and the load to be carried. For example, in a B-train, which is a train having a first or lead trailer connected to a second or pup trailer by a king pin and gooseneck connection, both the lead and pup trailers must have axles at specific longitudinal positions, both with respect to the king pin connection to the tractor, and, inter-axially with respect to the axles.
While having axles in specific longitudinal positions can be relatively easily accomplished when the trailer is a flat surface, this becomes more difficult for trailers which do not have flat surfaces. Accordingly, prior art trailers did not provide for easy transportation of non-flat loads on non-flat trailers and with axles located at the specific longitudinal positions required by government regulations.
Therefore, there has been a need in the art to provide non-flat trailers that can efficiently and easily accommodate loads having different configurations, and in particular loads which have curved configurations. In addition, there has been a need in the art to provide a frame for a trailer that can carry loads having curved configurations, but still provide the required number of axles at specific longitudinal positions, to comply with government regulations.